Impact of varying levels of expertise on decisions of category typicality

Experts on domains of basic level object categories possess extensive knowledge of features used to both individuate and categorize groups of similar members. Two studies were conducted to determine the impact of high knowledge on intermediate and advanced experts' typicality decisions for basic and subordinate level category exemplars, and to investigate whether the pattern of influence of factors (in particular, central tendency and subjective familiarity) remained fixed throughout the continuum of expertise. Example goodness increased as a function of the level of specificity of the category for which typicality was rated. Subjective familiarity was the principal determinant of typicality for individuals with high knowledge, whereas central tendency was related to typicality when knowledge was not particularly high. Advanced and intermediate experts produced similar ratings of typicality, indicating that individuals' decisions of typicality do not change markedly once intermediate levels of competency have been attained. The incorporation of knowledge effects into models of semantic memory, as well as interactions among knowledge, psychological factors, and environmental factors in determining typicality, are discussed.     

Analysis of movement patterns by elite male players of beach volleyball

The aim of this study was to analyse and compare movement pattems and direction of locomotion in professional men's beach volleyball. A quantitative analysis of beach volleyball play was carried out for 10 players in the European Beach Volleyball Championship 2005. Video recordings were made of the 1,997 movements in 4 matches. Analysis showed that male players used more offensive than defensive movement patterns. Defensive movement patterns were more blocks and defense than receptions. Offensive movement patterns were more attack and placements than attack preparation moves. Advance was the direction of locomotion most used. Identifying and understanding such movement patterns are vital to defining specific, effective training strategies for men's beach volleyball players.     

Motor expertise modulates movement processing in working memory

A substantial amount of literature has demonstrated individuals' tendency to code verbally a series of movements for subsequent recall. However, the mechanisms underlying movement encoding remain unclear. In this paper, I argue that sensorimotor expertise influences the involvement of motor processes to store movements in working memory. Experts in motor activities and individuals with limited motor expertise were compared in three experimental conditions assessing movement recall: (a) without suppression task, (b) with verbal suppression, and (c) with motor suppression. Athletes outperformed controls in movement recall, but the suppression tasks affected the two groups differently. Verbal suppression affected controls more than athletes, whereas the effect was reversed with motor suppression. Together, these findings suggest that controls and athletes favor different mechanisms to encode movements, either based on verbal or on motor processes, providing further evidence for a tight relationship between sensorimotor and cognitive processes.     

How structured and unstructured sport activities aid the development of expertise in volleyball players

This study sought to analyse self-reported perceptions of how the nature of sport activities undertaken by volleyball players aided their development. Thirty highly skilled and thirty less skilled players participated in retrospective interviews to identify the nature of activities undertaken in their developmental pathways. All players reported having an early-diversified sport involvement with participation in both structured and unstructured activities. Highly skilled players differed from less skilled players by having accumulated more hours of structured sport activities, some of which were undertaken with older peers. Furthermore, highly skilled players specifically highlighted the value of their involvement in particular unstructured activities with older peers and recognized their importance for expertise achievement. These findings illustrate the importance of considering the role of unstructured (in addition to structured) sport activities in the development of expertise in volleyball. Further work is needed to verify the generality of the findings to other sports.     

Domain specificity of spatial expertise: the case of video game players

Two experiments examined whether video game expertise transfers to performance on measures of spatial ability. In Experiment 1, skilled Tetris players outperformed non‐Tetris players on mental rotation of shapes that were either identical to or very similar to Tetris shapes, but not on other tests of spatial ability. The pattern of performance on those mental rotation tasks revealed that skilled Tetris Players used the same mental rotation procedures as non‐Tetris players, but when Tetris shapes were used, they executed them more quickly. In Experiment 2, non‐Tetris players who received 12 hours of Tetris‐playing experience did not differ from matched control students in pretest‐to‐posttest gains on tests of spatial ability. However, Tetris‐experienced participants were more likely to use an alternative type of mental rotation for Tetris shapes than were Tetris‐inexperienced participants. The results suggest that spatial expertise is highly domain‐specific and does not transfer broadly to other domains. Copyright © 2002 John Wiley & Sons, Ltd.     

Prediction of goal orientation and perceived competence on intensity and direction of precompetitive anxiety among adolescent handball players

This study explored the main and interactive effects of goal orientations and perceived competence on intensity and direction of the symptoms of precompetitive cognitive and somatic anxiety. 109 handball players from 16 high school teams (M = 16.2 yr., SD = 1.5) participated. All were asked to complete the Task and Ego Orientation in Sport Questionnaire, Perceived Competence Questionnaire, and a modified version of the Competitive State Anxiety Inventory-2. Using separated multiple hierarchical regression analyses, direction of the symptoms of precompetitive somatic anxiety was predicted by perceived competence and interaction of ego orientation x perceived competence. Perceived competence and the interaction of ego orientation x task orientation x perceived competence were significant predictors of direction of the symptoms of precompetitive cognitive anxiety. The results suggest that perceptions of competence and task orientation moderate the relationship between ego orientation and direction of the symptoms of precompetitive anxiety.     

Psychological movement patterns in psychotherapy

The following article represents a first step in the formulation of a method of experiential psychotherapy which integrates content and process areas of clinical practice. The integration is based on Eugene Gendlin's experiential understanding of psychotherapy (1973), and on an adaption of Rudolf von Laban's movement system (Dell 1970). The article focuses on the methodological issues of this integrative approach. For a fuller discussion of this new approach and of its clinical application, see Saner (1981).     

Perception of movement patterns: tracking of movement

The tracking of complex two-dimensional movement patterns was studied. Subjects were blindfolded, and their right hand moved around stencil patterns in the midsagittal plane, while the left hand concurrently reproduced the right-hand movement. The accuracy with which the left hand shadowed the criterion movements of the right hand was measured in shape and size. Right-hand movements were active or passive. Present tracking performance was contrasted with errors in recall reported by Bairstow and Laszlo (1978). Results showed that tracking performance was accurate. Active and passive criterion movements were tracked differently. Tracking was clearly superior to recall performance.     

Complexity and goodness of dot patterns varying in symmetry

Summary Two experiments were performed to specify stimulus determinants of pattern complexity and pattern goodness. Dot patterns distributed in 3×3 and 4×4 matrices with a rectilinear frame were used in Experiment 1, and dot patterns in hexagonal frameworks with a circular frame were used in Experiment 2. The patterns were invariant for transformations of rotation or reflection, and formed symmetry groups of different orders, i.e., cyclic and dihedral groups. The complexity and goodness of the patterns depended upon such stimulus variables as follows: (1) complexity decreased with the order of symmetry groups with equal weights for cyclic and dihedral groups, whereas goodness increased with the order of both symmetry groups with different weights; (2) the simplicity and goodness of patterns with a vertical axis were greater than those with a horizontal axis and those with an oblique one; (3) the complexity of the patterns that had collinear elements with equal length was rated the simplest; (4) pattern goodness increased as a function of the number of dots and the concentrations of dot to rotation/reflection axis in 3×3 and 4 × 4 matrices. Thus, complexity and goodness of pattern differed with respect to these stimulus variables.     

Common and specific gait patterns in people with varying anatomical levels of lower limb amputation and different prosthetic components

The present study’s aim was to identify the kinematic and kinetic gait patterns and to measure the energy consumption in people with amputation according to both the anatomical level of amputation and the type of prosthetic components in comparison with a control group matched for the gait speed. Fifteen subjects with unilateral transtibial amputation (TTA), forty with unilateral transfemoral amputation (TFA) (9 with mechanical, 17 with CLeg and 14 with Genium prosthesis) and forty healthy subjects were recruited. We computed the time-distance gait parameters; the range of angular motion (RoM) at hip, knee and ankle joints, and at the trunk and pelvis; the values of the 2 peaks of vertical force curve; the full width at half maximum (FWHM) and center of activity (CoA) of vertical force; the mechanical behavior in terms of energy recovery (R-step) and energy consumption. The main results were: i) both TTA and TFA show a common gait pattern characterized by a symmetric increase of step length, step width, double support duration, pelvic obliquity, trunk lateral bending and trunk rotation RoMs compared to control groups. They show also an asymmetric increase of stance duration and of Peak1 in non-amputated side and a decrease of ankle RoM in amputated side; ii) only TFA show a specific gait pattern, depending on the level of amputation, characterized by a symmetric reduction of R-step and an asymmetric decrease of stance duration, CoA and FWHM and an increase of Peak1 in the amputated side and of hip and knee RoM, CoA and FWHM in the non-amputated side; iii) people with amputation with Genium prosthesis show a longer step length and increased hip and knee RoMs compared to people with amputation with mechanical prosthesis who conversely show an increased pelvic obliquity: these are specific gait patterns depending of the type of prosthesis. In conclusion, we identified both common and specific gait patterns in people with amputation, either regardless of, or according to their level of amputation and the type of prosthetic component.     

Control of movement patterns in animals

As a more junior Fellow of the same college in Cambridge as Sir Frederic Bartlett, I am especially glad of this opportunity to join with members of the Experimental Psychology Society in honouring him. It would be superfluous for me to speak here of Sir Frederic's academic achievements: so many of our members are engaged in research on problems which sprung from his pioneering work, and his influence on the development of psychology as a science certainly needs no elaboration by me. But I would like to make one personal remark. I suppose all younger men feel that there are just a very few members of the preceding generation who have achieved a stature which will always be beyond the reach of any of their own contemporaries. Sir Frederic has always been one of those for me. I am speaking here not only of his academic achievements, but of his kindness as a man; and I would like to tell him how much I valued his willingness to share some of the benefits of his experience when I was blundering about on the borders of his subject.     

Four simultaneous component models for the analysis of multivariate time series from more than one subject to model intraindividual and interindividual differences

A class of four simultaneous component models for the exploratory analysis of multivariate time series collected from more than one subject simultaneously is discussed. In each of the models, the multivariate time series of each subject is decomposed into a few series of component scores and a loading matrix. The component scores series reveal the latent data structure in the course of time. The interpretation of the components is based on the loading matrix. The simultaneous component models model not only intraindividual variability, but interindividual variability as well. The four models can be ordered hierarchically from weakly to severely constrained, thus allowing for big to small interindividual differences in the model. The use of the models is illustrated by an empirical example.This research has been made possible by funding from the Netherlands Organization of Scientific Research (NWO) to the first author. The authors are obliged to Tom A.B. Snijders, Jos M.F. ten Berge and three anonymous reviewers for comments on an earlier version of this paper, and to Kim Shifren for providing us with her data set, which was collected at Syracuse University.     

Self-organization of coordinative movement patterns

We present a strictly operational approach — in which theoretical tools and experimental data are developed together — to the problem of understanding the coordination of movement patterns. The empirical aspects are guided by synergetics, a theory of spontaneous pattern formation in open systems. Following an outline of our theoretical strategy, recent experimental results are reviewed that demonstrate the validity of the approach. From these studies, it is possible to establish the linkage between order-order transitions in movement behavior and other nonequilibrium phase transitions in nature. Behavioral patterns (corresponding to low-dimensional attractors for collective variables) and their dynamics are shown to arise in a purely self-organized fashion from cooperative coupling among individual components. This step has been implemented analytically and computationally. The insights gained from the present research allow a generalization in the form of seven theoretical propositions that aim at characterizing pattern formation, stability and change in complex, biological systems. In turn, a number of new research directions emerge, including studies of the collective dynamics of the environment-movement system, learning, and multiple-limb coordination.     

Fourier analysis of movement patterns in pigeons

Fourier analysis describes the amount of variation in a time series by partitioning it into sinusoids of different amplitudes and wavelengths and quantifying the extent to which these waves are synchronized. The importance of a given wave is represented by its contribution to the explained variance of the time series. To illustrate its potential application to the study of movement, Fourier analysis was used to quantify the movement patterns of 2 pigeons on a variable-interval (VI) and a variable-time (VT) schedule of reinforcement. For comparison, the movements of 2 pigeons that did not receive reinforcement were similarly analyzed. Characteristic frequencies were higher during VI than during VT, and relatively low during nonreinforcement. We concluded that Fourier analysis can be used to represent movement patterns compactly, study their periodicity, stereotypy, and resonance, and assist in computer simulations and models of movement.     

Capturing and testing perceptual-cognitive expertise: A comparison of stationary and movement response methods

Numerous methods have been used to study expertise and performance. In the present article, we compare the cognitive thought processes of skilled soccer players when responding to film-based simulations of defensive situations involving two different experimental conditions. Participants either remained stationary in a seated position (n = 10) or were allowed to move (n = 10) in response to life-size film sequences of 11 versus 11 open-play soccer situations viewed from a player’s perspective. Response accuracy and retrospective verbal reports of thinking were collected across the two task conditions. In the movement-based response group, participants generated a greater number of verbal report statements, including a higher proportion of evaluation, prediction, and action planning statements, than did participants in the stationary group. Findings suggest that the processing strategies employed during performance differ depending on the nature of the response required of participants. Implications for behavioral methods and experimental design are discussed.     

Changing patterns of infant behavior and mother–infant interaction: Intra- and interindividual variability

Mother–infant dyads were observed weekly at their homes for a 15-month period. In this way longitudinal data about the infants’ crying, fretting/fussing, smiling and different types of physical contact with the mother were collected. The subject of this study concerns the variability and stability in macroscopic patterns of associations between these behaviors. Different types of associations were found between the behaviors, and most of them changed considerably as the infant developed. Individual differences in the nature of the associations and in the changes they underwent over time predominated, but in a limited number of cases the infants shared the same developmental trajectories of behavioral associations. The results show how the use of intensive time series designs can be advantageous in clarifying issues of long-term variability and stability in human behavior. They also support the notion of changing patterns of behavior being a normal feature of early development.     

Concurrent and retroactive interference effects in memory of movement patterns

Three experiments examined memory for enacted and observed movement patterns. The effect of visuo-spatial tracing tasks requiring overt motor movements, comparable to those required by the to-be-recalled movement pattern task when enacted, were compared with the effects of non-motor interference tasks, such as articulatory suppression and counting backwards. None of the experiments was able to detect indices of motor mechanisms in memory of movement patterns. The results are discussed in terms of theories of action memory and working memory and of a problem-solving account.     

Relative sensitivities to large-field optic-flow patterns varying in direction and speed

Motion in depth results in radial optic-flow patterns. Forward motion results in radially expanding patterns, whereas backward motion generates contracting patterns. Radial optic-flow patterns are typically represented with a positive speed gradient, ie zero speed at the point of fixation, and maximum speed at the periphery. However, the actual speed profile in such a stimulus will depend upon the relative depth of objects in the scene. Using large-field stimuli (82 deg diameter) we determined relative sensitivities to radial expansion and contraction patterns and also to various types of speed gradients: positive, negative, random, and flat. We found that, even when large-field stimuli are used, observers are more sensitive to radially contracting patterns than to expanding patterns. Sensitivity to the positive speed gradient was not consistently different from either the negative or random gradients. Sensitivity to the flat gradient depended upon the speed of the stimuli. The finding of greater sensitivity to radial contraction is discussed in terms of the functional requirements involved in the use of optic-flow signals in maintaining balance. On the basis of the present findings, the utility of comparing psychophysical results based on thresholds against physiological data based on suprathreshold stimuli is also discussed.